A medieval dagger with a spiral spring encased in the hilt which is wound by the pommel. Once the spring is wound, insert the sword in your hunting game (or an enemy if you're in a war) and the blade releases the power of the spring by rotating about its axis. When the spring is fully unwound a latch locks the blade so you can wind it up again. It uses no electricity.-- Amishman35, Oct 30 2006 The evolution of the dremel tool.-- 2 fries shy of a happy meal, Oct 30 2006 this reminds me of the 'anti-theft' mechanism of sword in the movie 'Blade'.-- xaviergisz, Oct 30 2006 One of the advantages of Japanese swords and knives over European styles is that the Japanese knife handles are almost always oval. European handles, on the other hand, are usually round, and can easily twist in the user's grip. I think a blade buried in flesh would provide more resistance to torque than a round handle could. This idea sounds like a neat way to twist your own dagger right out of your hand.-- baconbrain, Oct 30 2006 Maybe make the blade able to morph into a helical shape. Archimede's Dagger or some such.-- daseva, Oct 30 2006 But... where's the love?-- methinksnot, Nov 02 2006 random, halfbakery